1G INTAKE FLOW DATA

This test was conducted between a stock Mitsu intake manifold and one that was extruded. The numbers show for themselves of the CFM gain achieved when the extrude hone process is applied to intakes.

Each intake was bolted up to a full comp Level 4.5 head which was used for our baseline in testing. The test was done back to back, no changes done to the head, on a very typical high-humidity Oklahoma summer afternoon. The flowbench used was a Superflow 600 using the scale of 299 CFM of maximum suction (intake) and at a 28" testing pressure.

1G Stock Intake

The number highlighted in red represents the highest flowrate through the intake/head at a full valve lift of .400". It was simply calculated by taking 299 (which is the max airflow at Range #4 through a specifically sized and calibrated orifice within the flowbench) and multiplying it by .78 (the percentage of flow through the intake and head as a unit).  What does that mean? That means at the point of highest lift at the intake valves, 233.22 CFM was flowing through the intake/head combination. We use .400" as our baseline figure simply because the majority of cams out there today max out their lift at .400". The crazier cams that offer higher than .400" lift will, you guessed it, further increase the CFM through the intake/head.

1G Extrude Honed Intake

Now, check this out. The number in green shows that 8.37 more CFM is now flowing through the intake/head which equates to a 2.8% gain in flow over stock simply by having the intake manifold extrude honed. Furthermore, through past experience of dyno testing similar gains in percentages, this equates to a 15-20 horse gain. Indeed, Extrude Hones's claims are on par. Heck, just for yucks and grins, we've even bolted up a competitor's sheet metal intake and it didn't even hold a candle to these numbers. Surprised? Honestly, we were as well. Don't even ask whose...we'll be too busy asking for a slice of Canadian bacon at the local pizzeria.

Thought that extrude honed intakes were a bunch of bologna and waste of money? You be the judge.